Stator for electric machine

Abstract

Disclosed is a stator for an electric machine. The stator is provided with a stator core, and first and second series of coils each formed into a predetermined shape. Each of the coils in the first series is provided with a pair of first coil ends which respectively protrude from both end faces of the stator core. Each of the first coil ends is provided with a pair of bent portions which extend outward in the radial direction of the stator, and a bridge portion which connects the bent portions. Each second coil end is provided with a pair of upright portions and a bridge portion which connects the upright portions. The bridge portions of the coils in the first series are disposed outside the bridge portions of the coils in the second series in the radial direction of the stator. The bridge portion of each of the coils in the second series extends across the bent portions of two adjacent coils in the first series. The coils in the first series and the coils in the second series are configured so that each series includes a mixture of coils of at least two phases among a U-phase, a V-phase, and a W-phase. Each of the coils in the first series is connected to a coil of the same phase in the second series.

The invention claimed is: 
     
       1. A stator for an electric machine, the stator comprising:
 a stator core; 
 a plurality of teeth that extend into a first direction from the stator core and are arranged such that a slot is formed between adjacent teeth; 
 a first series of coils that are assembled into the slots and are formed into predetermined shapes; and 
 a second series of coils that are assembled into the slots and are formed into predetermined shapes, wherein 
 each of the first series of coils includes a pair of inserting portions respectively inserted into the slots, and a pair of first coil ends protruding from both end surfaces of the stator core, each of the first coil ends including a pair of bent portions extending from ends of the pair of inserting portions into a second direction that is opposite to the first direction, and a bridge portion that connects the bent portions with each other, 
 each of the second series of coils includes a pair of inserting portions respectively inserted into the slots, and a pair of second coil ends protruding from both end surfaces of the stator core, each of the second coil ends including a pair of upright portions extending from ends of the pair of inserting portions, and a bridge portion that connects the upright portions with each other, 
 the bridge portions of the first series of coils are disposed on the side toward the second direction with respect to the bridge portions of the second series of coils, the bridge portions of the second series of coils each extend across the bent portions of two adjacent first series of coils, 
 the first series of coils and the second series of coils are configured so that each series includes a mixture of coils of at least two phases among a U-phase, a V-phase and a W-phase, and each of the coils in the first series is connected to a coil of the same phase in the second series, and 
 the teeth include a plurality of stationary teeth and split teeth, the stationary teeth being integrally formed on the stator core such that the first series of coils and the second series of coils can be assembled to the stationary teeth, and each split tooth attached to the stator core at a position between adjacent stationary teeth. 
 
     
     
       2. The stator according to  claim 1 , wherein
 each coil in each phase in the first series is connected in series to a coil of the same phase in the second series, and 
 the number of coils of each phase in the first series is the same as the number of coils in the same phase in the second series. 
 
     
     
       3. The stator according to  claim 1 , wherein all of the first series of coils have the same shapes, and all of the second series of coils have the same shapes. 
     
     
       4. The stator according to  claim 1 , wherein half of all of the teeth are stationary teeth. 
     
     
       5. The stator according to  claim 1 , wherein the bridge portions of the first series of coils are disposed on the side toward the second direction with respect to the slots. 
     
     
       6. The stator according to  claim 1 , wherein
 the stator core is cylindrical in shape, 
 the teeth are arranged along a circumferential direction of the stator core, 
 the teeth extend from an inner circumferential surface of the stator core into the first direction, and 
 the bridge portions of the first series of coils are disposed on the side toward the second direction of the stator core with respect to the slots. 
 
     
     
       7. The stator according to  claim 6 , wherein
 the bridge portions of the first series of coils are disposed on a first circumference formed around a center axis of the stator core, and 
 the bridge portions of the second series of coils are disposed on a second circumference that is on the side toward the first direction with respect to the first circumference. 
 
     
     
       8. The stator according to  claim 7 , wherein the inserting portions of the first series of coils and the inserting portion of the second series of coils are disposed on the second circumference.